Add synctable command into caravel

caravel/bin/caravel

@@ -7,6 +7,7 @@ from __future__ import unicode_literals
 import logging
 from datetime import datetime
 from subprocess import Popen
+from collections import defaultdict
 
 from flask_migrate import MigrateCommand
 from flask_script import Manager
@@ -125,6 +126,67 @@ def refresh_druid():
             "[" + cluster.cluster_name + "]")
     session.commit()
 
+@manager.option(
+    '-p', '--prefix', default="",
+    help="Sync Table Prefix")
+@manager.option(
+    '-d', '--database', default=None,
+    help="Specifies database (use caravel db name, not real db name)")
+def synctable(prefix, database):
+    ''' Sync DB Table with Caravel Table'''
+    print("")
+
+    if (prefix == "" and database is None) or (database == 'main' and prefix == ""):
+        print("If you not set prefix and db name, some system table may be sync to caravel.")
+
+        check_status = raw_input("Are you sure do this? (Y/N)").lower().strip()
+        if check_status not in ['y', 'yes']:
+            print("Exit sync table")
+            exit()
+
+    if database is None:
+        caravel_dbs = db.session.query(caravel.models.Database).all()
+    else:
+        caravel_dbs = (db.session.query(caravel.models.Database)
+                                 .filter_by(database_name=database).all())
+
+    if caravel_dbs == []:
+        print("Database not exists, please check database name")
+        exit()
+
+    existing_tables = []
+    for row in db.session.query(caravel.models.SqlaTable).all():
+        existing_tables += [(row.database.database_name, row.name)]
+
+    # Get all need insert table
+    insert_dict = defaultdict(list)
+    for caravel_db in caravel_dbs:
+        for table_name in caravel_db.get_sqla_engine().table_names():
+            table = (caravel_db.database_name, table_name)
+
+            if (table not in existing_tables) and table_name.startswith(prefix):
+                insert_dict[caravel_db].append(table_name)
+
+    # Insert to caravel tables
+    count_insert = 0
+    for caravel_db, tables in insert_dict.items():
+        for table_name in tables:
+            count_insert += 1
+
+            tbl = caravel.models.SqlaTable(table_name=table_name)
+            tbl.description = ""
+            tbl.is_featured = False
+            tbl.database = caravel_db
+            db.session.add(tbl)
+            db.session.commit()
+            tbl.fetch_metadata()
+
+            print("[{db}] {table} insert success.".format(
+                db=caravel_db.database_name, 
+                table=table_name
+            ))
+
+    print("[{}] Sync table complete.".format(count_insert))
 
 if __name__ == "__main__":
     manager.run()